Introduction
In recent years in Ethiopia, there is an increment of the number of participants in volleyball sport under clubs, projects and recreational programs. However, athletes are highly vulnerable for injuries because of a lack of protective equipment, suitable playing areas, medical facilities, efficient injury surveillance systems and skilled manpower (coaches).The aim of this study was to examine the incidence and mechanisms of acute and overuse volleyball injuries in Ethiopia and to describe factors associated with injuries.
Methods
The injury incidence rate, severity, diagnosis and anatomical location of the injuries that occurred during practice and competition in a full season of 40 weeks were recorded prospectively on a weekly basis during the period 2015/16. A total of 323 volleyball players (168 female and 155 male) from Amhara Regional State Clubs and youth teams were participated in the study. All players responded to a questionnaire on demographic variables (only at baseline), sports participation, use of preventive measures, and previous injuries and conducted baseline functional tests (balance, power and flexibility). Volleyball exposure during training and matches was recorded for each individual player by the coach on a weekly exposure form. In the case of an injury triage nurses interviewed the injured player and recorded it on an injury registration form on a weekly basis.
Results
In the current study, the overall mean age of the players was 15.97 ± 2.94 years for men and 15.86 ± 2.33 years for women. In terms of team type, the age of youth players was 15.42 ± 1.92 years for females and 14.85 ± 1.05 years for males, and club players was 18.54 ± 2.81 years for females and 21.54 ± 2.98 years for male players. During the period of the study (10 months) the total sample (n=323) reported 188 injuries. It is notable that, injury rate in relation to age, the 323 players were divided into three age-related groups. Of the 131 youth and club injured players, 118 (62.77%) players aged 14–16 years, 65 (34.57%) players aged 17–25 and 5 (2.66%) players aged more than 25. The injury rate in the age range of 14–16 players was statistically different in comparison to the injury rate to the other age groups (χ2=5.89, p≤0.05). Both youth and club players, reported 188 injuries during a total exposure time 50 379 player-hours, comprising 43 566 hours of training (7 715 hours for club and 35 851 hours for youth players) and 6 813 hours of match play (1 004.5 hours for club and 5 808.5 hours for youth players). The overall injury incidence was 3.73 injuries/1000 player-hours, with 4.31 injuries/1000 player-hours for males and 3.26 injuries/1000 player-hours for females. Regarding team type, 7.1 injuries/1000 player-hours was for club players and 3.02 injuries/1000 player-hours for youths. During match play the injury incidence was 27.59 per 1000 player-hours and 4.31 per 1000 player-hours throughout training periods. The rate of injury in game sessions was statistically different in comparison to training injury rate (χ2=16.1,p≤0.05). The result also revealed the rate of injury in game session was significantly different in club and youth players (χ2=9.14,p≤0.005) but there were no differences in relation to gender in both game and training sessions. During the season 167 (88.83%) were acute injuries and 21(11.17%) overuse syndromes. According to physician diagnosis, the most common injury was the fingers (55 cases, 29.25%), followed by ankle (35 cases, 18.61%), knee (33 cases, 17.55%). Significant difference was obtained between the anatomical parts (p≤0.05) and gender (p≤0.005). The severity of injuries was shown in terms of absence from competition or training after the injury. The rate of mild injuries was 53.19 % (100 cases), that of moderate injuries was 36.70 % (69 cases), and that of major injuries was 10.11 % (19 cases) (significant difference between them, χ2=35.18, p≤0.05). Statistical differences between severities of injury in relation to gender was observed (female χ2=18.6,p≤0.05 and male χ2=17.19,p≤0.05). Regarding the factors of injury, 57.45% (108 cases) was due to poor technique, 14.89% (28 cases) because of incorrect sprawls, 7.98% (15 cases) caused by stepping on others’ feet and 8.51% (16 cases) as a result of fatigue and significal difference was obtained between the factors of injuries (p≤0.05) but not gender (p>0.05).
Conclusions
This is the first large scale study of its kind in Ethiopia and has established the epidemiology of injury related to volleyball. Overall, the findings of this study revealed that the frequency of injury was high (58.2%) in the 2015/16 season of volleyball played. In this study male players were more injured than females 51.6% (97/188) and 48.4 % (91/188) respectively. But significant difference was not found between gender (p>0.05). Interms of team type significantly youth players 126 (67.02%) were more injured than elites 62 (32.98%) (p≤ 0.05). Injuries in both groups gender and team type were much more likely to occur in games than in practice. But, significance difference was found only between club and youth players (p=0.05). Finger (29.25%), ankle (18.62%) and knee (17.55%) were the most frequent injured anatomical parts and significant difference was found between the overall anatomical sites (p≤0.05). Sprain was clearly the most common injury in volleyball which accounted nearly about one third 31.38% (59/188) of all injuries with an incidence of 1.17 per 1000 player-hours followed by dislocation and laceration 21.27% (40/188) with an incidence of 0.79 per 1000 player-hours each and statistically significant between the type of injuries diagnosed (p≤0.05) but no significant difference between male and female players (p>0.05). In this prospective study, 10.64% (20 cases) left/right front and 11.7% (22 cases) back line club players and 19.68% (37 cases) back court and 17.55% (33 cases) center young players were vulnerable to injuries due to poor technique 57.45% (108 cases), incorrect sprawl 14.89% (28 cases), fatigue 8.5% (16 cases) and steps on other’s feet 7.98% (15 cases) during the execution of blocking, setting a ball for spikers and receiving first ball. Statistically, significant difference was not obtained between players court position (p>0.05). In relation to degree of severity, more than half 53.19 % (100 cases) injuries were mild severe, 36.7% (69 cases) moderate and 10.1% (19 cases) were major severe. In this regard significance difference was found (p≤0.05).
Recommendations
In order to prevent players from musculoskeletal injuries, specific warming up, strength, proprioceptive, plyometric, balance and flexibility exercises for the muscles and joints of the upper and lower extremities of players should be incorporated in the training sessions. In addition, players should use preventive equipment during training and match periods. Moreover, continuous injury surveillance and intervention is needed.